Purpose: Corneal hysteresis (CH) is a corneal biomechanical property measured by the ocular response analyzer (ORA). It is associated with primary open-angle glaucoma development, progression, and severity as well as intraocular pressure (IOP) measurement. Decreases in CH and changes in IOP measurements have been described for laser-assisted refractive surgery; however, patients with prior radial keratotomy (RK) have not been examined. Read More

Authors:

Institute of Ophthalmology, Department of Surgical Sciences, University of Turin, Turin, Italy.

Radial keratotomy is a refractive surgical technique, widely used in the 80s and early 90s to correct myopia and astigmatism, but now overcome by more recent laser techniques. Important consequences, often in patients with more than 45 years of age, are progressive hyperopic shift and/or an increase in corneal astigmatism, whose main cause seems to be an increase in the curvature radius of the central portion of the cornea. This seems to be due to radial keratotomy incisions - with the consequent need for cross-linking - intraocular pressure, and corneal biomechanical parameters. Read More

Methods: In a retrospective non-comparative interventional case series, outcomes in 6 consecutive eyes of 4 patients with residual refraction after radial keratotomy were analyzed after the implantation of ICLs. All of the lenses were implanted to correct the residual refractive error, ranging from -12. Read More

Authors:

Aim: To develop a new manometric device for intravital measurement of intraocular pressure (IOP) in the anterior chamber and to assess tonometric data reliability, including post-radial keratotomy (RK) measurements.

Material And Methods: The experiment was conducted in 2 isolated cadaver eyes, while the clinical study enrolled 20 patients (21 eyes) scheduled for cataract phacoemulsification surgery. Of them, 10 patients (10 eyes) with immature cataract and mild to moderate myopia constituted the control group. Read More

Methods: In 95 eyes of 65 patients, using the actual refraction following cataract surgery as target refraction, the predicted IOL power for each method was calculated. The IOL prediction error (PE) was obtained by subtracting the predicted IOL power from the implanted IOL power. Read More

Methods: Eight patients with cataract (12 eyes) after RK were treated in our hospital from March, 2010 to June, 2013. The visual acuity, keratometric power and length of the ocular axis were examined before the operation. Read More

Authors:

Purpose: To evaluate in a pilot study the visual, refractive, corneal topographic, and aberrometric changes after wavefront-guided LASIK or photorefractive keratectomy (PRK) using a high-resolution aberrometer to calculate the treatment for aberrated eyes.

We report the case of a 46-year-old female patient who was referred to our clinic (Orasis Eye Clinic, Reinach, Switzerland) seeking improvement of her distance and near visual acuity. Radial keratotomy (RK) was performed at a younger age on both eyes to correct -5 D myopia. The patient underwent a bilateral same-session multifocal corneal excimer femtosecond laser (Supracor) keratomileusis correction. Read More

A 24-year-old male patient with bilateral high myopia presented to our outpatient department with sudden onset of pain and diminution of vision in his right eye. He had sequentially undergone bilateral trabeculectomy and photorefractive keratectomy at the age of 6 years in both eyes. This was followed by radial keratotomy in right eye at the age of 8 years. Read More

Authors:

Purpose Of Review: Treatment of hyperopia presents greater challenges than treatment of myopia for multiple reasons, including the fact that hyperopia tends to progress with age and becomes more symptomatic with the loss of accommodation.

Recent Findings: Despite these issues, surgeons have multiple options to treat hyperopia successfully. Modern laser vision correction has high success rates for most patients and performs acceptably in the presence of high hyperopia or high cylinder. Read More

Authors:

Results of femtosecond based intrastromal astigmatic keratotomy have been reported to be encouraging for correction of Astigmatism. We report a new surgical technique-manual intrastromal corneal keratotomy (MICK) for correction of simple refractive astigmatism (-1.5 DC against the rule). Read More

Authors:

Purpose: To report a novel application of collagen cross-linking (CXL) in refractive astigmatic enhancement of previously performed astigmatic keratotomy.

Methods: A 28-year-old woman with prior history of bioptics correction of high myopic astigmatism with femtosecond laser-assisted astigmatic keratotomy followed by topography-guided LASIK showed long-term regression of the astigmatism 4 years later. A novel CXL application was employed in an attempt to reverse the regression of the astigmatic keratotomy. Read More

Authors:

Department of Ophthalmology and Visual Sciences, University of Illinois College of Medicine at Chicago, Chicago, IL 60612, USA.

The introduction of the excimer laser for keratorefractive surgery in the 1990 s permanently reshaped the treatment landscape for correcting refractive errors, such as myopia, hyperopia, and astigmatism. Until that point, these treatments had relied on less predictable techniques, such as radial keratotomy and automated lamellar keratectomy. In recent years, other new technologies, along with increased understanding of the basic science of refractive errors, higher-order aberrations, biomechanics, and the biology of corneal wound healing, have allowed for a reduction in the surgical complications of keratorefractive surgery. Read More

Background: Precise IOL calculation in post-refractive surgery patients is still a challenge for the cataract surgeon. The purpose of this study is to test whether adding Orbscan II values into the double-K method improves IOL calculation in this group of patients.

To report a case of corneal rupture due to blunt trauma occurring 20 years after radial keratotomy (RK) and transverse keratotomy. A 57-year-old woman sustained direct blunt trauma to her right eye. Ocular examination revealed a ruptured globe involving two of the eight RK incisions connected together across the visual axis with iris incarceration in the wound. Read More

Authors:

Purpose: To illustrate the hypothesis that corneal vertex centration is superior to entrance pupil centration when guiding an ablation by wavefront.

Methods: In one case example of therapeutic retreatment for treatment zone decentration after primary radial keratotomy (RK) centered on the entrance pupil (line of sight), both a whole-eye wavefront-guided ablation profile (WASCA data) and a topography-guided ablation profile (Atlas data) were generated using the CRS-Master (Carl Zeiss Meditec) and compared. The patient had a large vertical angle kappa. Read More

Authors:

We report a topography-wavefront-guided repair procedure in a patient with a decentered optical zone and significant higher-order aberrations (HOAs) following radial keratotomy 14 years previously. The CRS-Master custom ablation software was used to generate a topography-wavefront-guided ablation profile based on Atlas front corneal surface topography data, and the MEL 80 excimer laser was used to treat the patient. Very high-frequency digital ultrasound scanning (Artemis) was performed before and after surgery to measure epithelial and stromal thickness changes to evaluate the anatomical congruity of the planned and achieved irregular ablation. Read More

Authors:

Purpose: To characterize the epithelial thickness profile in a population of eyes after radial keratotomy for myopia.

Methods: The epithelial thickness profile was measured in vivo by Artemis very high-frequency digital ultrasound arc-scanning (ArcScan Inc) across the central 10-mm diameter of the cornea on 14 eyes after radial keratotomy for myopia. Maps of the mean and standard deviation of epithelial thickness were plotted and compared to the epithelial thickness of a previously published population of normal untreated eyes. Read More

Authors:

We describe the femtosecond laser-assisted midperipheral multilayer intrastromal ablation technique, which combines the benefit of radial keratotomy, ie, not disturbing the optical zone, with currently available technology to correct myopia. The technique was performed in 2 patients, both of whom experienced a decrease in mean corneal power. In 1 patient, the manifest refraction improved, with a 1-line increase in uncorrected visual acuity 1 day postoperatively. Read More

A 28-year-old male who underwent uneventful radial keratotomy for myopic correction 8 years earlier presented with sudden decrease in vision in the right eye. Slitlamp examination revealed 16 healed radial corneal scars in both eyes along with marked corneal edema and conjunctival congestion in the right eye. The Scheimpflug cross-sectional image of the right cornea displayed an intrastromal aqueous cleft in communication with the anterior chamber, consistent with the diagnosis of acute hydrops. Read More

Department of Ophthalmology, Paulista School of Medicine, Federal University of Sao Paulo, Brazil.

Purpose: To present the prospective application of the Orbscan II central 2-mm total-mean corneal power obtained by quantitative area topography in intraocular lens (IOL) calculation after refractive surgery.

Methods: Calculated and achieved refraction and the difference between them were studied in 77 eyes of 61 patients with previous radial keratotomy (RK), RK and additional surgeries, myopic LASIK, myopic photorefractive keratectomy (PRK), or hyperopic LASIK who underwent phacoemulsification without complications in 3 eye centers. All IOL calculations used the average from the central 2-mm Orbscan II total-mean power of maps centered on the pupil without the use of previous refractive data. Read More

Authors:

Purpose: To evaluate the accuracy of central corneal power measurements by Scheimpflug imaging (Pentacam) for eyes that had corneal refractive surgery.

Methods: This study comprised two groups: a pilot group of 100 eyes with prior hyperopic or myopic LASIK that did not have cataract surgery, and a test group of 41 eyes with prior radial keratotomy (RK) and cataract surgery. In the pilot group, Pentacam images and refraction were taken preoperatively and 3 months after LASIK. Read More

Authors:

Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Japan.

Objectives: To report a case of acute high hyperopia occurring after radial keratotomy and evaluate the extent of corneal wavefront aberration with a Hartmann-Shack aberrometer.

Methods: A 45-year-old man had undergone bilateral radial keratotomy with four incisions for myopia 15 years earlier. The patient developed significant hyperopia and irregular corneal astigmatism in the left eye after the operation, reducing his best-corrected visual acuity. Read More

Authors:

Purpose: The purpose of this study was to report arcuate keratotomy (AK) as a treatment for post-laser in situ keratomileusis astigmatism arising from incorrect axis treatment.

Method: A 52-year-old woman presented with decreased vision in her left eye. Three months previously, the patient had undergone laser in situ keratomileusis in her left eye with incorrect axis treatment. Read More

Authors:

Purpose: To assess the efficacy, safety, and accuracy of TOSCA II (Topography Supported Custom Ablation) treatments for the correction of high corneal aberrations and refractive error following previous ocular surgery.

Setting: Jules Stein Eye Institute, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, California, USA.

Methods: In this combined retrospective and prospective clinical study, patients who had cataract surgery after corneal refractive surgery were recalled to have Scheimpflug imaging of the operated cornea and Holladay EKR determination. Read More

Authors:

Purpose: To evaluate the outcome of primary or retreatment photorefractive keratectomy (PRK) or phototherapeutic keratectomy (PTK) with mitomycin C (MMC) 0.02% applied prophylactically intraoperatively for the prevention of haze and regression in cases of significant haze and regression after primary PRK, due to previous radial keratotomy (RK), in primary PRK eyes with high myopia, and in comeas with a previous superficial foreign body scar.

Methods: This was a retrospective evaluation of 34 eyes treated with PRK or PTK and intraoperative MMC. Read More

Authors:

In 1995, a 46-year-old woman was referred for refractive surgery. Eleven years earlier, she had undergone an uncomplicated penetrating keratoplasty in her right eye to treat a dense corneal opacity caused by contact lens-related microbial keratitis. Due to high myopia in the graft, she was unable to achieve useful vision and declined contact lens use. Read More

Authors:

Objective: To investigate the long-term loss and variation of corneal endothelial cells after radial keratotomy.

Methods: By the way of case-control study, 51 myopia (101 eyes) patients who underwent RK in Beijing Friendship hospital, from January 1989 to December 1996 is the RK group. 51 myopia (102 eyes) outpatients who have no other eye diseases is the control group. Read More

Authors:

Since approval of the use of the excimer laser in 1995 to reshape the cornea, significant developments in the correction of refractive errors such as myopia, hyperopia, and astigmatism have been achieved. Combined with other advanced ophthalmological instruments (e.g. Read More

Authors:

Purpose Of Review: Since their introduction in the mid-1990s, surface ablation techniques have continued to evolve, enabling surgeons to give patients better quality of vision with less postoperative pain. The purpose of this chapter is to discuss that evolution, the common techniques used today, and how to address potential complications.

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